In which window is better to light
Question
Answer
It’s better to light in the window that looks out into the street. It’s better to light over a busy street, even if practically fewer people will see you Chanukkah lights, and even if it’s in a less busy part of the house. And if there is no street over which you can light, not even a side street, then it’s better to light over a private yard where there is a lot of traffic. If there is no other choice, then it’s enough that the lights be visible from the building across from you.
Source
Tractate Shabbos, folio 21b, see the argument between the commentary of Rashi and the commentary of the Tosaphos. See Shulchan Oruch, section Orach Chaim, chapter 671, §5; See Azamrah LiShmecha Newsletter, # 117. The Shulchan Oruch (ibid.) explains that Chanukkah candles have to be lit in a door or a gate that’s close to a public domain. And if someone lights in a window, it’s proper that the chanukiah also be visible from a public domain. Only if there is no better choice, is it permissible to light in a place, where people will see it from a building across or from a private yard, even though there is a lot of traffic there. Therefore, it’s preferable to light in a place that overlooks public domain (and even a small side street is considered public domain, even though it’s difficult to see the lights from that side street). Only if it’s impossible to light over public domain, one should light over a place where there are many people coming and going, even though it’s a private property.